Electrical loads, such as lamps, ceiling lighting fixtures, thermostats, shades, etc., may be controlled using load control devices. A load control device may be configured for wireless communication. For instance, a dimmer switch may be configured for radio-frequency wireless communication (e.g., configured as an RF dimmer switch). Such a load control device may be associated with one or more devices in a load control system, such as a lighting control system. A load control device that participates in a load control system may receive wirelessly communicated messages (e.g., including commands) from one or more other devices of the load control system. The messages may cause the load control device to adjust the amount of power delivered to one or more electrical loads that are connected to the load control device.
FIG. 1 depicts an example prior art lighting control system 10 that includes a tabletop RF dimmer switch 20 and a lamp 30 that is plugged into the dimmer switch 20, such that the dimmer switch 20 may be operated to control the amount of power delivered to the lamp 30. The dimmer switch 20 may be electrically connected to an electrical circuit that includes an alternating-current (AC) power source 40 and an AC outlet 42 that is electrically connected to the AC power source 40. The AC outlet 42 includes an upper switched receptacle 41 and a lower unswitched receptacle 43. The electrical circuit further includes a wall-mounted switch 46 that is coupled in series electrical connection between the AC power source 40 and the upper switched receptacle 41. The lamp 30 may be controlled by the wall-mounted switch 46. The dimmer switch 20 includes a plug 22 that is plugged into the switched receptacle 41. The lamp 30 includes a plug 32 that is plugged into the plug 22 of the dimmer switch 20, such that the delivery of AC power to the lamp 30 may be controlled via the wall-mounted switch 46.
The lighting control system 10 may further include one or more devices that are configured to wirelessly communicate with the dimmer switch 20. As shown, the lighting control system 10 includes an occupancy and/or vacancy sensor 50, a daylight sensor 60, and a remote control device 70, such as a remote keypad. One or more of the occupancy and/or vacancy sensor 50, the daylight sensor 60, and the remote control device 70 may wirelessly communicate with the dimmer switch 20 via RF signals 90, for example to command the dimmer switch 20 to adjust the amount of AC power that is provided to the lamp 30.
Control of the illustrated lighting control system 10 may be compromised when power is removed from the upper switched receptacle 41 of the outlet 42. For instance, when the wall switch 46 is turned off, a wireless communication component of the dimmer switch 20, such as a receiver, may be unpowered and thus unable to receive wirelessly communicated commands. This may undesirably render the dimmer switch 20 unresponsive to wirelessly communicated commands from the occupancy and/or vacancy sensor 50, the daylight sensor 60, and the remote control 70, such as commands to turn on, turn off, or dim the lamp 30.
Plugging the dimmer switch 20 into the lower unswitched receptacle 43 of the outlet 42 may ensure continuous power of the wireless communication component of the dimmer switch 20, but would remove the ability to switch power to the lamp 30 using the wall-mounted switch 46. This may be undesirable to a user of the lighting control system 10. A user of the lighting control system 10 may prefer to be able to switch power to the lamp 30 via the wall-mounted switch 46, while ensuring that the lamp 30 remains controllable by the dimmer switch 20, for instance via one or more of the occupancy and/or vacancy sensor 50, the daylight sensor 60, and the remote control 70.